Submission #795729

#	Time	Username	Problem	Language	Result	Execution time	Memory
795729		1bin	Let's Win the Election (JOI22_ho_t3)	C++14	32 / 100	187 ms	2320 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e5 + 5;
const int inf = 1e6;
const double eps = 1e-10;
int n, k, a, b;
double dp[505][505];
vector<pair<int, int>> v;

double solve(int x){
    double ret = 0;
    for(int i = 0; i <= n; i++)
        for(int j = 0; j <= n; j++) dp[i][j] = 1e9;
    dp[0][0] = 0;
    for(int i = 1; i <= n; i++){
        auto&[b, a] = v[i - 1];
        for(int j = 0; j <= min(i, x); j++){
            dp[i][j] = dp[i - 1][j] + 1.0 * a / (x + 1);
            if(j && b != inf) dp[i][j] = min(dp[i][j], dp[i - 1][j - 1] + 1.0 * b / j);
        }
    }
    if(dp[n][x] > 1e9 - eps) return 1e9;
    vector<double> t;
    int j = x;
    for(int i = n; i; i--){
        auto&[b, a] = v[i - 1];
        if(abs(dp[i][j] - dp[i - 1][j] - 1.0 * a / (x + 1)) < eps) t.emplace_back(1.0 * a / (x + 1));
        else ret += dp[i][j] - dp[i - 1][j - 1], j--;
    }
    sort(all(t));
    for(int i = 0; i < k - x; i++) ret += t[i];
    return ret;
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> n >> k;
    for(int i = 0; i < n; i++){
        cin >> a >> b;
        if(b == -1) b = inf;
        v.emplace_back(b, a);
    }
    sort(all(v));
    double ans = inf;
    for(int i = 0; i <= k; i++) ans = min(ans, solve(i));
    cout << fixed << setprecision(10) << ans;
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'double solve(int)':
Main.cpp:20:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   20 |         auto&[b, a] = v[i - 1];
      |              ^
Main.cpp:30:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   30 |         auto&[b, a] = v[i - 1];
      |              ^

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 33
• Subtask 6: 11 / 11
• Subtask 7: 0 / 23